Pressure venting circuit for respiratory humidification apparatus
An improved humidifier assembly includes a tubing and a one-way valve for equalizing pressure between gas space of a water supply container and gas space of a humidifier vessel.
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Humidifying apparatus such as disclosed in U.S. Pat. Nos. 4,110,419, 4,172,105, 4,366,105, 4,500,480, 4,674,494, 4,765,327 and 6,050,552 describe different variations of cartridge-type humidification systems and apparatus incorporating a heated humidifier module connected via tubing to a water supply reservoir. In these systems, the humidification chamber is installed within a heater receptacle. As water is evaporated in the heated humidification chamber replacement water is fed to the cavity from the adjacent water supply reservoir. The descriptions of the aforesaid patents are incorporated herein by reference.
In U.S. Pat. Nos. 4,500,480 and 6,050,552, a water level sensing tube positioned in the humidification chamber communicates with the air space above the water level in the water supply reservoir via tubing with a one-way valve. Water is fed to the humidification chamber from the bottom of the reservoir via tubing, also provided with a one-way valve. During continuous gas flow, for example, where the humidification apparatus is used with a CPAP system or is connected to a respirator or ventilator which directs respiratory gas into the humidification chamber under pressure, the pressure in the water supply reservoir equals the pressure to which the humidification chamber is exposed. Under certain conditions, the humidification cartridge may be exposed to pressures of 150 cm H2O or more during continuous gas flow, or pressures in excess of 120 cm H2O during intermittent gas flow. The high pressure is transferred ultimately to the reservoir via the one-way tube so that the pressure inside the reservoir is near or equal to the mean pressure to which the humidification chamber is exposed. During typical operation, such high pressures in the containers of the system are not problematic. However, sudden pressure reduction in the humidification chamber can result in rapid transfer of water from the reservoir and flooding of the chamber and even into the respiratory gas tubing to a patient. The apparatus described herein is designed to substantially reduce or eliminate such flooding.
SUMMARY OF THE INVENTIONThe apparatus disclosed herein provides for transfer of fluid (gas) from the water supply reservoir to the humidification chamber to equalize pressure differential between the humidification chamber and the reservoir. More specifically, the apparatus functions to allow pressure gas in the space above water level in a water supply container to be directed to the space above water level in a humidifier vessel. In a preferred embodiment, the pressure equalizing apparatus comprises tubing communicating the air space above the water level in both the humidification chamber and the water reservoir, and a one-way valve in or cooperating with the tubing allowing fluid flow in the tubing from the water reservoir to the humidification chamber.
The invention includes a method for equalization of pressure differential, the humidifier chamber and water supply reservoir. More specifically, the method provides for delivering higher pressure in the water supply reservoir by venting the high pressure gas to the air space in the humidification chamber. Means for carrying out the method include piping and valving between the air spaces in the water supply reservoir and the humidifier vessel.
In
The humidifier assembly also includes a water supply container and reservoir 30 having a port 32 adjacent to the upper end or top of the reservoir and communicating with the interior space of the reservoir, above the water level. Adjacent to the bottom end of the reservoir 30 is a port 34. Water from the reservoir is supplied via tubing 28, one end which is attached to port 34 on the reservoir 30 and the other end to water inlet nipple 22 of the humidifier vessel. The water supply tubing 28 is provided with a check valve or one-way valve 26 which allows water to be directed from the reservoir 30 to the humidifying vessel 10. Tubing 25 adjacent to the upper portion of the assembly is secured to port 32 on the water reservoir 30 and to water level control port 18 on the cap 16 of the humidifier vessel 10. Tubing 25 is also provided with a check valve or one-way valve 23 which allows fluid to pass from the humidifier vessel to the water reservoir. Further description and operation of the apparatus shown in
Observing also
In operation of the humidifier assembly shown in
During operation of the apparatus which is connected to a ventilator, pressure in the humidifier vessel increases relative to the reservoir 30 as previously discussed. This relatively high pressure in the humidifier vessel is transferred to the reservoir via tubing 25 and one-way valve 23 whereby the water level in pipe 20 equalizes the pressure between the two containers. Thus, during continuous gas flow through the humidifier vessel, the pressure in the reservoir is equalized with the pressure within the humidifier vessel. When pressure in the humidifying vessel is suddenly changed, for example, when the pressurized vessel is disconnected from a respirator, the pressure in the water holding cavity is suddenly exposed to atmospheric pressure creating a substantial pressure gradient between the humidification chamber and the reservoir. In the prior art apparatus illustrated in
Undesirable flooding of the humidifier vessel is prevented by the apparatus illustrated in
Claims
1. A humidifier assembly comprising
- a water supply container enclosing a water containing reservoir;
- a humidifier vessel comprising a water holding cavity having an inlet adjacent to the bottom thereof, a respiratory gas inlet, a respiratory gas outlet, a gas pressure vent port, a water level control port, and a water level control pipe communicating with said water level control port;
- a first one-way valve for directing gas flow through said water level control pipe to said water supply container;
- a second one-way valve for directing gas flow from said water supply container to said gas pressure vent port;
- first piping for directing water from said water supply container to said humidifier vessel;
- second piping cooperating with said first one-way valve and said second one-way valve for equalizing pressure between said water supply container and said humidifier vessel; and wherein said second piping comprises tubing extending between said water supply container and said gas pressure vent port and said water level control port.
2. A humidifier assembly of claim 1 wherein said first one-way valve is located in said water level control pipe.
3. A humidifier assembly of claim 2 wherein said second one-way valve is located in said humidifier vessel between said water level control port and said water holding cavity above water level therein.
4. A humidifier assembly of claim 1 wherein said second one-way valve is located in said humidifier vessel between said water level control port and said water holding cavity above water level therein.
5. A humidifier assembly of claim 1 including a water level control port tubing adapter cooperating with said water level control port and wherein said second piping comprises tubing attached to said water level control port tubing adapter.
6. A humidifier of claim 1 including a third one-way valve cooperating with said first piping for directing flow of water from said water supply container to said humidifier vessel.
7. A humidifier assembly of claim 1 including a cartridge disposed in said water holding cavity, said cartridge having a walled hollow interior isolated from said water holding cavity and wherein said cartridge displaces between about 20% and about 80% of the volume of said water holding cavity.
8. A humidifier vessel for cooperating with a water supply container for providing humidification in a respiratory circuit comprising:
- a humidifier vessel comprising a water holding cavity having an inlet adjacent to a bottom of the water holding cavity, a cover for enclosing an upper end of the humidifier vessel having a respiratory gas inlet, a respiratory gas outlet, a gas pressure vent port, and a water level control port;
- a water level control pipe communicating with said water level control port;
- a first one-way valve for directing gas flow through said water level control pipe to a water supply container;
- a second one-way valve communicating with a tubing for directing gas flow from said water supply container to said humidifier vessel; and said tubing extending between said water supply container and said gas pressure vent port and said water level control port.
9. A humidifier vessel of claim 8 including a cartridge disposed in said water holding cavity, said cartridge having a walled hollow interior isolated from said water holding cavity and wherein said cartridge displaces between about 20% and about 80% of the volume of said water holding cavity.
10. A humidifier assembly comprising:
- a humidifier vessel comprising a water holding cavity having an inlet adjacent to a bottom end of said water holding cavity, a respiratory gas inlet and a respiratory gas outlet each communicating with said water holding cavity adjacent to a top of said water holding cavity, a first port and a generally vertical pipe having an open upper end communicating with said first port and an open lower end for contacting water in said water holding cavity, and a second port communicating with said water holding cavity adjacent to the top of said water holding cavity;
- a water supply container enclosing a water containing reservoir;
- first tubing having one end communicating with said water holding cavity via said inlet and another end communicating with said water containing reservoir adjacent to the bottom thereof, and a first one-way valve cooperating with said first tubing for directing water from said water supply container to said humidifier vessel;
- second tubing having one end communicating with said first port and another end communicating with said water containing reservoir above water level therein, and a second one-way valve cooperating with said second tubing for directing fluid from said pipe to said water containing reservoir; and
- third tubing having a first end communicating with said second port and a second end communicating with said water containing reservoir above water level therein, and a third one-way valve cooperating with said third tubing for directing gas from said water containing reservoir to Said Water holding cavity.
11. A humidifier assembly of claim 10 wherein said humidifier vessel comprises an open top shell forming said water holding cavity and a cap member secured in substantially fluid tight seal to the upper end of said shell and enclosing the open top thereof, and wherein said respiratory gas inlet, respiratory gas outlet, first port and second port are formed in said cap member.
12. A humidifier assembly of claim 11 wherein said second end of said third tubing communicates with said second tubing between said second one-way valve and said water containing chamber.
13. A humidifier assembly of claim 10 wherein said second end of said third tubing communicates with said second tubing between said second one-way valve and said water containing chamber.
14. A humidifier assembly of claim 13 including a tee adapter secured to said second tubing and said third tubing between said second one-way valve and said water containing chamber for communicating said second tubing with said third tubing.
15. A humidifier assembly of claim 10 including a cartridge disposed in said water holding cavity, said cartridge having a walled hollow interior isolated from said water holding cavity and wherein said cartridge displaces between about 20% and about 80% of the volume of said water holding cavity.
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Type: Grant
Filed: Jun 29, 2004
Date of Patent: Jun 12, 2007
Patent Publication Number: 20050284475
Assignee: Teleflex Medical Incorporated (Limerick, PA)
Inventor: Thomas C. Loescher (Rancho Santa Fe, CA)
Primary Examiner: Justine R. Yu
Assistant Examiner: K C Matter
Attorney: Baker & Hostetler LLP
Application Number: 10/881,944
International Classification: A61M 15/00 (20060101); A61M 16/10 (20060101); A61M 15/08 (20060101); B01D 19/00 (20060101); B01D 14/00 (20060101); B01D 53/14 (20060101); B65D 83/00 (20060101);